Story ID: 510 SABRE Reaction Engines
ESA Gives Sabre Hypersonic Engine a Boost
By: Chris Pocock
Caption: This week at Farnborough Reaction Engines also announced the creation of a U.S.-based subsidiary
Word Count: 515
The future for hypersonic flight could be firing up some momentum. Breakthrough hypersonic propulsion technology described here at Farnborough yesterday could revolutionize access to space by reusable launch vehicles, and enable flights from London to Sydney in just four hours. Equally, if not more important, Reaction Engines (Hall 4 Stand H98) said it now has sufficient funds to ground-test its Synergetic Air-Breathing Rocket Engine (Sabre) by the end of the decade. BAE Systems took a 20 percent stake in the privately-held British company last November.

Mark Wood, chief operating officer and engineering director, said that independent assessments by the European Space Agency (ESA) and the U.S. Air Force Research Laboratory (AFRL) have validated Reaction Engines’ advanced combined-cycle technology, which enables an air-breathing engine to reach more than Mach 5 before transitioning to rocket mode to achieve orbital velocity at up to Mach 25.

The company announced the signing of a €10 million ($11.1 million) contract with ESA, adding to £50 million ($66.2 million) already promised from the UK Space Agency and £20 million ($26.5 million) from BAE’s buy-in. Wood said the company would now expand its employee count from 60 to 100. Reaction Engines was founded in 1989 and previously attracted enough private investment (about £50 million/$66.2 million) to advance the SABRE design to Technology Readiness Level 3-4.

Philippa Davies, turbomachinery team leader, said that the company’s lightweight heat exchanger or pre-cooler was a key to Sabre. Helium under pressure is passed through thousands of tubes in spiral modules. After passing through a two-shock axisymmetric intake with a moveable centerbody, air as hot as 1,000 degrees C enters this pre-cooler around the outer circumference and flows radially inwards, being cooled to minus 150 deg C in less than 1/100th of a second. In the middle of the engine, a turbo-compressor accepts air at a constant inlet temperature of 400 deg C and constant 1 bar pressure. The rocket combustion chambers and four nozzles are at the rear.

Another key to Sabre will be the ultra-high vacuum furnace at the company’s base in Culham, Oxfordshire, which will enable high-fidelity ground testing at relatively low cost. Close to Culham is Brite Precision, a subsidiary company that does high-precision machining of the engine parts. Also not far away is the Wescott rocket testing facility.

Reaction Engines (Hall 4 Stand 98) has done preliminary design of a lightweight re-usable launch vehicle named Skylon that could operate from runways to space orbit and back. But the company says that Sabre is highly scalable to a range of air and space vehicles, such as the potential hypersonic airliner. In a separate briefing here yesterday, BAE Systems showed potential defense applications of a Mach 5 air-breathing platform.

Having spent many years and many millions of dollars trying to develop similar re-usable space launchers, the U.S. is keeping a close eye on progress by Reaction Engines. In early 2014, the British company signed a Cooperative Research and Development Agreement (Crada) with the AFRL. This week, Reaction Engines announced the creation of a U.S.-based subsidiary that will engage with potential US government and industry partners.